Nonvolatile memory is one of the indispensable elements in modern electronic devices, but most of the nonvolatile memories in the market are still the one based on silicon substrate. However, the traditional nonvolatile floating gate memories fabricated on monocrystalline silicon substrate are difficult to fabricate on the glass substrate due to the complicated fabricating method and high process temperature, and that will lead them subject to many restrictions when they are applied on the display panel.
Recently, a new nonvolatile memory based on thin film transistor (TFT) structure has aroused great attention. This type of nonvolatile memory not only can be fabricated on glass or flexible substrate but also has a good compatible with traditional TFT manufacturing process, thus the nonvolatile memory has a good prospects in the future advanced system panel or system package technology. Most of the present researches about the TFT memory still use the polycrystalline silicon as the channel material. However, it was reported that the TFT memories based on polycrystalline silicon do not have a good program/erase efficiency and data retention. Furthermore, when a bias stress is applied on source or drain electrode, there appears a large variation on threshold voltage.
Thus a new type of TFT memory with good program/erase efficiency, long data retention and stable threshold voltage is necessary.